How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PESTS
Flea beetles are present throughout the growing season but are primarily a concern in the month following transplanting.

The adult Epitrix fuscula flea beetle is a small (2 mm), black beetle, whereas E. hirtipennis is brown. Like all flea beetle adults, their hind legs are thickened, allowing them to jump rapidly. Eggs are laid in the soil near the bases of plants. They hatch in about one week and larvae remain in the soil and feed on roots for 2 to 3 weeks. They pupate in the soil and after 7 to 10 days, adults emerge and move to the plant where they feed on leaves for 2 months or more.

The adult palestriped flea beetle, Systena blanda, is about 0.12 inch (3 mm) long and has a shiny brown body with a broad white stripe down each wing.

Most flea beetles overwinter in the adult stage in plant debris in the field, on field margins, and in adjacent areas. Adults emerge in spring to feed and lay eggs.

DAMAGE
Flea beetle adults can be very destructive to young plants, often defoliating and killing them. They cause the greatest damage by feeding on cotyledons, stems, and foliage. Older leaves/plants are usually more tolerant of their feeding.

MANAGEMENT
The key to preventing flea beetle damage is early detection.

Cultural Control
Methods that may provide partial control of these beetles, which can be especially important in organically certified crops, include the use of trap crops such as Chinese Southern Giant Mustard (Brassica juncea var. crispifolia), interplanting with radishes ('Chinese Daikon' or 'Snow Belle'), the use of row covers, white or yellow stick traps, and good field sanitation. For more information on cultural control options, see Flea Beetle: Organic Control Options.

Organically Acceptable Methods
Cultural controls and sprays of PyGanic or the Entrust formulation of spinosad are acceptable for use on an organically certified crop.

Monitoring and Treatment Decisions
Monitor young transplants every few days the first month after planting for damage because flea beetles can move quickly into a field. If damage is detected, consider a treatment to prevent loss of plants.

Common name		Amount/Acre**	R.E.I.+	P.H.I.+
(trade name)			(hours)	(days)
When choosing a pesticide, consider information relating to impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used.
A.	PERMETHRIN*
	(Pounce) 25WP	6.4–9.6 oz	12	3
	MODE OF ACTION GROUP NUMBER1: 3
B.	ESFENVALERATE*
	(Asana XL)	5.8–9.6 fl oz	12	7
	MODE OF ACTION GROUP NUMBER1: 3
C.	SPINOSAD
	(Entrust)#	1.25–2.5 oz	4	1
	(Success)	4–8 oz	4	1
	MODE OF ACTION GROUP NUMBER1: 5
	COMMENTS: Early treatment provides only about 50% suppression of flea beetles, but the Entrust formulation is an organically acceptable alternative. Do not exceed 29 fl oz of Success or 9 oz of Entrust/acre/crop.
D.	PYRETHRIN#
	(PyGanic) 1.4EC	Label rates	12	0
	MODE OF ACTION GROUP NUMBER1: 3
	COMMENTS: Short residual material; always buffer pyrethrin to pH 5.5 or lower.
**	See label for dilution rates.
+	Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
*	Permit required from county agricultural commissioner for purchase or use.
#	Acceptable for use on organically grown produce.
1	Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.

PUBLICATION

UC IPM Pest Management Guidelines: Eggplant
UC ANR Publication 3475
Insects and Mites
R. H. Molinar, UC Cooperative Extension Fresno County
J. L. Aguiar, UC Cooperative Extension Riverside County
M. J. Jimenez, UC Cooperative Extension Tulare County
P. B. Goodell, UC IPM, Kearney Agricultural Center, Parlier

Top of page